JP2007524340A - Armature with single coil and commutator - Google Patents

Abstract

An armature for an electric motor having a single coil and an armature is disclosed. The armature includes a coil having inner and outer winding portions each separated by an insulator and each including a plurality of sheet metal conductors, and a plurality of sheet metal commutator segments each formed integrally with one of the conductors. And a commutator. In one embodiment of the armature, the outer diameter of the commutator is smaller than the outer diameter of the coil. In the same or different armature embodiments, the commutator segments are wider than the conductors. The armature is manufactured from a pair of conductive sheets, and each of the conductive sheets forms a plurality of conductive bands each having a first and second conductor portion, and the conductive sheets are formed into an inner cylinder and an outer cylinder. Forming an inner cylindrical conductive sheet inside the outer cylindrical conductive sheet, forming a coil from the first cylindrical conductive sheet of the inner cylindrical conductive sheet and the outer cylindrical conductive sheet; It is manufactured by forming a commutator from the conductive sheet and the second conductor portion of the outer cylindrical conductive sheet.
[Selection] Figure 3

Description

background

Field
[0001] The present disclosure relates to an electric motor, and more particularly to an armature of an electric motor.

background
[0002] Brush motors, particularly brush motor armatures, are typically fabricated using separate components for commutators and coil windings. These components need to be assembled separately and require bonding techniques to electrically connect the coil windings to the commutator. Soldering, welding, pressure welding, or various other manufacturing techniques are currently used to electrically connect these components.

  [0003] Accordingly, the brushless motor technology requires a coil and commutator arrangement without the conventional electrical connections previously used. If these electrical connections can be eliminated, it will be possible to reduce the size of the motor armature, improve the reliability of the armature (and thus the motor), and reduce the cost of manufacture.

Overview

  [0004] In one aspect of the invention, an armature of an electric motor includes a coil having an inner winding portion and an outer winding portion separated by an insulator. Each of the winding sections includes a plurality of sheet metal conductors and a commutator having a plurality of sheet metal commutator segments each formed integrally with one of the conductors. The commutator has an outer diameter that is smaller than the outer diameter of the coil.

  [0005] In another aspect of the invention, an armature of an electric motor includes a coil having an inner winding and an outer winding separated by an insulator. Each of the winding sections includes a plurality of sheet metal conductors and a commutator having a plurality of sheet metal commutator segments, each commutator segment being formed integrally with one of the conductors, It has a width wider than the width.

  [0006] In yet another aspect of the present invention, a method of manufacturing an armature from a pair of conductive sheets includes a plurality of each including a first conductor portion and a second conductor portion in each of the conductive sheets. Forming a conductive sheet, forming a conductive sheet into an inner cylinder and an outer cylinder, disposing the inner cylindrical conductive sheet inside the outer cylindrical conductive sheet, and an inner cylindrical conductive sheet Forming a coil from the first conductor portion of the first conductive portion and the first conductive portion of the outer cylindrical conductive sheet; and the second conductive portion of the inner cylindrical conductive sheet and the second conductive portion of the outer cylindrical conductive sheet. Forming a commutator having an outer diameter smaller than the outer diameter of the coil from the conductor portion.

  [0007] In yet another aspect of the invention, a method of manufacturing an armature from a pair of conductive sheets includes a plurality of conductive sheets, each including a first conductor portion and a second conductor portion. Forming a conductive sheet, forming a conductive sheet into an inner cylinder and an outer cylinder, disposing the inner cylindrical conductive sheet inside the outer cylindrical conductive sheet, and an inner cylindrical conductive sheet Forming a coil from the first conductor portion of the first conductive portion and the first conductive portion of the outer cylindrical conductive sheet; and the second conductive portion of the inner cylindrical conductive sheet and the second conductive portion of the outer cylindrical conductive sheet. Forming a commutator from the conductor portion, the commutator including a plurality of commutator segments each having a width wider than the width of the first conductor portion.

  [0008] It is understood that other embodiments of the present invention will become readily apparent from the detailed description, wherein the various embodiments of the present invention have been shown and described by way of illustration. Of course, the present invention is capable of other and different embodiments without departing from the spirit and scope of the present invention, and some details of the invention may be modified in various other ways. It is. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not as restrictive.

  [0009] Aspects of the invention are described in the accompanying drawings for purposes of illustration and not limitation. In the accompanying drawings, like reference numerals refer to similar elements.

Detailed description

  [0017] The detailed description set forth below in connection with the appended drawings is intended as a description of various embodiments of the invention and is not intended to represent the only embodiments in which the invention may be practiced. Each embodiment described in this disclosure is provided merely as an example or illustration of the present invention and should not necessarily be construed as preferred or advantageous over other embodiments. The detailed description includes specific details for the purpose of providing a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without these specific details. In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the present invention. Acronyms and other descriptive terms are used merely for convenience and clarity and are not intended to limit the scope of the invention.

  [0018] Various embodiments described throughout this disclosure are directed to ironless core armatures of brushed DC motors. The armature may be a thin wall, tubular, stand alone component with a coil and commutator having a single structure. The diameter of the rectifier may be reduced to allow the brush to operate at a lower surface speed and reduce drag and heat generation. The single structure reduces the axial space in the motor that would otherwise be required to accommodate the armature, eliminating the need to join the coil and commutator.

  [0019] Reference is now made to FIGS. 1A and 1B. The armature is a substantially mirror image and may be composed of a pair of thin pieces of bare sheet metal plates 10 and 10 'that are conductive and precision machined. Plates 10 and 10 'may be reinforced copper grade 110 or any other suitable material. Plates 10 and 10 'may be about 0.005 inches (0.12 mm) thick and 2 inches x 3 inches (about 5 cm x 7.5 cm). Other dimensions and materials can be used to manufacture plates 10 and 10 'depending on the particular application.

  [0020] Each plate 10 and 10 'is processed to produce a series of generally parallel conductors. In at least one embodiment of the armature, the parallel conductors are formed with a space between them that is about 1 to 1.5 times the thickness of the conductor. Each conductor can have coil portions 12 and 12 'formed in a chevron pattern and commutator portions 14a, 14b, 14'a and 14'b formed in a relatively straight pattern. The commutator section conductor may include commutator segments 14a and 14a ', with support strips 14b and 14b' between each commutator segment 14a and 14a '. The desired pattern is achieved by precision cutting the plate by chemical processing. The desired pattern can also be processed by alternative techniques such as water jet cutting, laser cutting, electron beam cutting, stamping, progressive die, or other conventional processing methods.

  [0021] The plate 10 can include carrier strips 16a and 16b at each edge, and the plate 10 'can include carrier strips 16a' and 16b 'at each edge. The carrier strip is used to support the conductor. The desired pattern may further include a series of relatively small pads, such as pads 18a and 18b on plate 10 and pads 18a 'and 18b' on plate 10 '. The diameter of each pad is about 0.25 mm, or any other suitable size. The total number of pads is approximately equal to twice the number of conductors. It will be appreciated that this type of armature is made from plates and pads having conductors that increase or decrease depending on the particular brushless motor application.

  [0022] The plate 10 is wound into a thin-walled hollow cylindrical shape, such as the cylindrical body 20 of FIG. 2A. The plate 10 'is similarly wound into a thin-walled hollow cylindrical shape, such as the cylinder 20' of FIG. Combined. The diameter of the cylinder 20 may be about 0.510 inches and the diameter of the cylinder 20 'may be about 0.520 inches. The cylinder 20 is formed with a slightly smaller diameter so as to allow subsequent axial alignment of the cylinder 20 within the cylinder 20 'to form an armature. For this reason, the cylinder 20 ′ is hereinafter referred to as the outer cylinder 20 ′ and the cylinder 20 is referred to as the inner cylinder 20. Other sizes of cylindrical diameters may be used.

  [0023] Next, the inner cylinder 20 is placed on the axis of rotation and is shown in FIG. 3 with 4-5 layers of the highest grade industrial grade glass strand having a thickness of generally about 0.00015 inches. 24 is tightly wound around the coil portion of the conductor while avoiding the pad of the inner cylindrical body 20. Rigid wrapping of multiple layers of glass fiber strands over the coil portion of the conductor generally provides structural support for the tubular structure. The glass fiber layer can also provide some degree of physical separation and accompanying electrical insulation between the inner cylinder 20 and the outer cylinder 20 '. The thickness of the glass fiber layer may be about 0.00075 inch and is therefore relatively small, but sufficient strength can be added. The covered inner cylinder 20 is then inserted to the back of the outer cylinder 20 ′, with the coaxial axial alignment of both cylinders and the outer cylinder 20 ′ of each pad on the inner cylinder 20. Ensure matching with the corresponding pad above. The next step is to wrap the layer of industrial grade glass fiber strands tightly over the coil portion of the conductor of the outer cylinder 20 'in a manner similar to that performed for the inner cylinder 20. This glass fiber layer can provide additional structural support. The thickness of the outer cylindrical glass fiber layer may be about 0.001 inch.

  [0024] The coil portions of the inner and outer cylindrical conductors are either soldered or electrically attached at their respective pads to form a continuous inductive helical coil. The pad can provide a solder flow path using, for example, a lead, silver, tin solder material that can withstand an operating temperature as high as 450 degrees Fahrenheit (“F”). The pads may be welded rather than soldered to create an interconnect with copper as the base weld material, allowing for higher armature temperatures during operation. Alternative methods of interconnecting pads such as pressure welding, spot welding, or laser welding can be used. When welding is used, the armature operating temperature can be raised to about 600 degrees Fahrenheit, which is the utilization temperature of encapsulant that is applied later. Matched pads 18a, 18a 'and 18b, 18b' are not required unless the solder is the selected bonding material, respectively.

  [0025] The soldered joint electrically interconnects all of the coil portions of the conductors of the inner cylinder 20 with the corresponding coil portions of the outer cylinder 20 'to provide a continuous connection as shown in FIG. A guided helical structure is formed. FIG. 4 shows an example of a coil on an armature that illustrates in detail how part of the helical structure of the coil is achieved. For example, the conductor coil portion 12a of the inner cylindrical body 20 is electrically connected to the conductor coil portion 12a ′ of the outer cylindrical body 20 ′ by soldering the pads 18c and 18c ′ to each other and joining them in another case. Connected to. The other end of the conductor coil portion 12a is electrically connected to the conductor coil portion 12b ′ of the outer cylindrical body 20 ′ by soldering the pads 18d and 18d ′ to each other and by joining them in another case. . The remaining conductor coil portions of the inner cylinder 20 are interconnected in the same manner as the corresponding conductor coil portions of the outer cylinder 20 'so that the total number of interconnects at each end is the same. In essence, the conductor coil portion 12 of the inner cylinder 20 provides the half (half) of the electrical circuit, and the conductor coil portion 12 'of the outer cylinder 20' provides the other half of the circuit. The electrical circuit is completed by joining the two halves.

  [0026] Once the coil is formed, the carrier strips 16a and 16b on the inner cylinder 20 and the carrier strips 16a 'and 16b' on the outer cylinder 20 'are removed. The removal of the carrier strip can include the removal of the support strips in both cylinders of the armature. The remaining commutator segment of the inner conductor 20 is then electrically connected to the remaining commutator segment of the outer cylinder 20 'by soldering, crimping, or other means.

  [0027] Reference is now made to FIGS. The armature 22 may further include an aluminum flywheel 24 formed with a disk-shaped portion 26, and the disk-shaped portion 26 is bonded to the inner cylindrical body by an electrically insulating bonding means. A cylindrical portion 28 extending in the axial direction from the disk-shaped portion 26 is designed to have a reduced diameter. After the flywheel 24 is inserted into the armature 22, the commutator segment is deformed inwardly around the cylindrical portion 28 and bonded to the cylindrical portion by an electrically insulating adhesive means. The outer surface of the cylindrical portion 28 is formed with a slot 30 to improve adhesion to the inner surface of the flywheel commutator. The flywheel 24 includes an output drive shaft 32 disposed in the axial direction, and the output drive shaft 32 is firmly attached to the flywheel 24.

  [0028] Prior to installation of the output drive shaft, the armature 22 is impregnated into the encapsulated compound, adding additional structural stability, permanently securing all components and providing complete electrical isolation of the device. Is done. In particular, the armature 22 is impregnated with an encapsulated polyimide, for example, a polyimide composed of 25% solids / solute (polyimide) and 75% solvent (NMP). The armature 22 is centrifuged, poured, dipped, impregnated or encapsulated to replace all voids with the polyimide solution. Centrifugal force pushes air out of the structure and pushes the polyimide deep into the clevis and cracks of the telescoping tubular structure, allowing permanent adhesion and insulation of the components.

  [0029] The polyimide-impregnated armature 22 is heat cured, for example, at a temperature of about 500 degrees Fahrenheit, resulting in a solvent-free, hardened and cured polyimide encapsulated armature. The limit on cure temperature is typically a solder flow temperature of about 550 degrees Fahrenheit, but the use of non-solder welding techniques allows for polyimide cure at 695 degrees Fahrenheit and an armature operating temperature of 600 degrees Fahrenheit. . Other porcelain materials such as ceramic, glass, silicate, silicon and the like may be used. After the armature 22 is thermally cured, it can be cooled to room temperature.

  [0030] The commutator segments on the armature 22 are used to provide a smooth cylindrical rotating surface for the brush to distribute current to the coil. When the support strip is removed from the armature 22, the number of remaining commutator segments is half the number of coil conductors. This configuration allows the commutator to form a cylindrical structure having a smaller diameter than the coil. A cylindrical cavity 34 delimited by a coil is adapted to accommodate a cylindrical field stator assembly (not shown) for various motor or generator applications.

  [0031] While particular embodiments of the present invention have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the invention. For example, the brushless motor in an alternative embodiment is configured to generate electricity when the shaft is rotated by mechanical means. Accordingly, the present invention is not intended to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novelty disclosed herein. It is.

It is a top view of a pair of precision-cut copper plates used in the armature. It is a top view of a pair of precision-cut copper plates used in the armature. 1B is a front perspective view of the copper plate of FIG. 1A wound in the shape of a hollow cylinder used in an armature. FIG. 1C is a front perspective view of the copper plate of FIG. 1B wound in the form of a hollow cylinder used in an armature. FIG. FIG. 4 is a front perspective view of the cylinder of FIG. 2 inserted into the cylinder of FIG. 3 to form an armature. FIG. 6 is a schematic diagram showing interconnection of conductive loops to form a continuous cylindrical conductive coil of an armature. It is a longitudinal cross-sectional view of an armature. FIG. 6 is a cross-sectional view of the armature of FIG. 5 taken along section line 6-6.

Claims (26)

A coil having an inner winding portion and an outer winding portion each separated by an insulator, each including a plurality of sheet metal conductors;
Each having a plurality of sheet metal commutator segments integrally formed with one of the conductors, and a commutator having an outer diameter smaller than the outer diameter of the coil;
An armature for an electric motor.   The commutator segment includes at least a first layer and a second layer, and the first layer of the commutator segment and the conductor of the outer winding portion are formed of a first sheet metal, and the rectifier The armature of claim 1, wherein the second layer of segments and the conductor of the inner winding portion are formed from a second sheet metal.   The armature of claim 1, wherein each of the commutator segments has a width that is wider than a width of a corresponding conductor.   The armature according to claim 1, wherein the number of commutator segments is less than the number of conductors of the outer winding portion.   Further comprising a flywheel having a first portion supporting the coil and a second portion supporting the commutator, wherein the first portion has an outer diameter greater than the outer diameter of the second portion; The armature according to claim 1.   The armature of claim 5, further comprising a shaft that extends axially through the flywheel. The insulator comprises a first non-conductive filament wound around the inner winding;
The armature further comprises a second non-conductive filament wound around the outer winding portion and a polyimide enclosing the commutator and the coil,
The first filament and the second filament are impregnated with polyimide,
The armature according to claim 1. A coil having an inner winding portion and an outer winding portion each separated by an insulator, each including a plurality of sheet metal conductors;
A commutator having a plurality of sheet metal commutator segments;
With
Each of the commutator segments is integrally formed with one of the conductors and has a width wider than the width of the corresponding conductor;
The armature of the motor.   The commutator segment includes at least a first layer and a second layer, the first layer of the commutator segment and the conductor of the outer winding portion are formed of a first sheet metal, and the commutator segment The armature according to claim 8, wherein the second layer and the conductor of the inner winding portion are formed from a second sheet metal.   The armature according to claim 8, wherein the commutator has an outer diameter smaller than an outer diameter of the coil.   Further comprising a flywheel having a first portion that supports the commutator and a second portion that supports the coil, the first portion having an outer diameter that is smaller than the outer diameter of the second portion; The armature according to claim 10.   The armature of claim 12, further comprising a shaft that extends axially through the flywheel.   The armature according to claim 8, wherein the number of commutator segments is less than the number of conductors of the outer winding portion. The insulator comprises a first non-conductive filament wound around the inner winding;
The armature further includes a second non-conductive filament wound around the outer winding portion, and a polyimide enclosing the commutator and the coil,
The first filament and the second filament are impregnated with polyimide,
The armature according to claim 8. A method of manufacturing an armature from a pair of conductive sheets,
Forming a plurality of conductors each having a first conductor portion and a second conductor portion on each of the conductive sheets;
Forming the conductive sheet into an inner cylinder and an outer cylinder;
Disposing the inner cylindrical conductive sheet inside the outer cylindrical conductive sheet;
Forming a coil from the first conductor portion of the inner cylindrical conductive sheet and the first conductor portion of the outer cylindrical conductive sheet;
Forming a commutator having an outer diameter smaller than the outer diameter of the coil from the second conductor portion of the inner cylindrical conductive sheet and the second conductor portion of the outer cylindrical conductive sheet;
A method comprising:   The method of claim 15, wherein forming the commutator includes removing one or more second conductor portions from the armature.   The method of claim 16, wherein each remaining second conductor portion constitutes a commutator segment having a width wider than the width of the corresponding first conductor portion. Further comprising inserting a flywheel into the armature;
The flywheel has a first portion configured to support the coil and a second portion configured to support the commutator, the first portion being the second portion. The method of claim 15, having an outer diameter that is greater than   The method of claim 18, further comprising inserting a shaft through the flywheel.   Winding a non-conductive filament around the first conductor portion of the conductive sheet of the inner cylinder, winding a non-conductive filament around the first conductor portion of the conductive sheet of the outer cylinder, and the electric machine The method of claim 17, further comprising: applying polyimide to the armature to encapsulate a child and impregnate the non-conductive filament. A method of manufacturing an armature from a pair of conductive sheets,
Forming a plurality of conductors each including a first conductor portion and a second conductor portion on each of the conductive sheets;
Forming the conductive sheet into an inner cylinder and an outer cylinder;
Disposing the inner cylindrical conductive sheet inside the outer cylindrical conductive sheet;
Forming a coil from the first conductor portion of the inner cylindrical conductive sheet and the first conductor portion of the outer cylindrical conductive sheet;
Forming a commutator from the second conductor part of the inner cylindrical conductive sheet and the second conductor part of the outer cylindrical conductive sheet, wherein the commutators correspond to the corresponding ones Including a plurality of commutator segments having a width wider than the width of the first conductor portion;
A method comprising:   The method of claim 21, wherein forming the commutator includes removing one or more second conductor portions from the armature.   The method of claim 21, wherein the outer diameter of the commutator is smaller than the outer diameter of the coil. Further comprising inserting a flywheel into the armature;
The flywheel has a first portion configured to support the coil and a second portion configured to support the commutator, the first portion being the second portion. 24. The method of claim 21, wherein the method has an outer diameter that is greater than the outer diameter.   25. The method of claim 24, further comprising inserting a shaft through the flywheel.   Winding a non-conductive filament around the first conductor portion of the conductive sheet of the inner cylinder, winding a non-conductive filament around the first conductor portion of the conductive sheet of the outer cylinder, and the electric machine The method of claim 21, further comprising: applying polyimide to the armature to encapsulate a child and impregnate the non-conductive filament.

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